22 
brackets on the left refer back to permit the retracing of 
steps. 
Of the four statements in gronp 1, Ic — ‘‘paired fins, 
both pectorals and ventrals fanshaped” — fits the fish and 
refers forward to group 3 ; here 3b refers forward to 5 ; 
5b to 13 ; 13b to 14 ; 14b to 16 ; 16a to 17 ; 17a fits the fish 
and determines it as Lates calcarifer (Bloch), the giant 
perch. 
Whilst the greater part of this key has been compiled 
independently, the separation of the eels is based on 
Schmidt (1928), and the identification of the goby- 
gudgeon group is largely adapted from McCulloch and 
Ogilby (1919). Provisionally, the fire-tailed gudgeons have 
been listed as Carassiops galii Ogilby, with the suppression 
of Caras-Hiops klunzingen' Ogilby, and Whitley’s (1935) 
compression of the perchlets has been carried further in 
view of work in progress with the recognition of only one 
black-tipped perchlet — Amba.ssis agassizi Steindachner. 
Pigures of most of the fish dealt with are accessible in 
“The Fishes and Fish-like Animals of New South Wales” 
(McCulloch, 1927). No detailed list of references is 
attached as this would seem out of place in a paper of 
this nature: but the serious worker may refer to 
McCulloch (1929) for full references up to that date. 
Since 1929, though some species have disappeared in 
synonymy, and a fe^v generic names have been changed, 
only one new fish {Craterocephalus marjoriae Whitley, 
1948) has been described that has been identified from the 
region under consideration. 
The authors thank Mr. G. Mack, Director of the Queens- 
land Museum, for permission to examine types of Ambassids 
in the Museum collection, and Mr. Tom Marshall, Govern- 
ment Ichthyologist, Department of Harbours and Marine, 
Brisbane, for making available his collection and for 
checking for omission the list of fish dealt with. The need 
for this key was suggested by Professor W. Stephenson, 
Professor of Zoology, University of Queensland, whose 
sustained interest has been greatly appreciated. 
KEY 
I a Paired fins, both pectoral and ventral, leaf-shaped 
paddles--Neoceratodus forsteri (Gunther) : Queensland 
lung-fish, ceratodus. 
b. Paired fins, pectorals fan-shaped, ventrals absent — Eels, 2. 
c. Paired fins, both pectoral and ventral, fan-shaped — 3. 
d. Paired fins, pectorals fan-shaped, ventrals small finger- 
like bodies, situated in front of peo^orals — Gadopsis 
marmoratus Richardson : River blackfish. 
